One way or the other, summer seemed certain to usher in change in Denver. With a number of high-profile pending free agents and a desire to continue improving the team after a tremendously successful 2013-14 campaign, the Avalanche management group was busy both on the trade front and in unrestricted free agency.

But activity doesn't always translate to improvement, and it isn't at all clear that Colorado is a better team now than it was a few days ago.

Between trade and free agency, the team is essentially replacing four departing players with four others:

Avalanche additions and subtractions

Departure

Average 82 games

Arrival

Average 82 games

Paul Stastny

24 goals, 59 points

Jarome Iginla

31 goals, 65 points

P.A. Parenteau

22 goals, 64 points

Daniel Briere

17 goals, 43 points

Brad Malone

6 goals, 14 points

Jesse Winchester

8 goals, 21 points

Andre Benoit

7 goals, 27 points

Brad Stuart

4 goals, 16 points

NHL.com

Average 82-game performance based on the last three seasons for each player.

The raw numbers don't look great, and in each case, the Avs added a player who was older than the one he was replacing on the roster.

Iginla is 37, as Briere will be early in October, and Stuart turns 35 in November. Those three key players are all in their twilight years and all reasonably high risks to fall off a performance cliff—though both Stuart and Briere are in the final years of their current deals, which minimizes risk.

Looking at the moves in more detail doesn't help matters much.

Bruce Kluckhohn/Getty Images

Colorado's exceptional depth at centre—Matt Duchene, Nathan MacKinnon, Ryan O'Reilly and John Mitchell can all play top-nine minutes at the position—means that subbing in a winger such as Iginla for Stastny isn't a problem positionally.

What does hurt is that Stastny played tougher minutes than Iginla—both saw a high quality of competition, but Iginla had a pile of offensive-zone starts, while Stastny generally started in the defensive zone—and drove possession, while Iginla relied heavily on finishing ability and had middling shot metrics.

Some might say "tomayto, tomahto," but Iginla's numbers are going to get worse if he isn't given the kind of favourable usage he had in Boston—and that means Stastny's defensive zone load will shift to someone else.

The loss of Stastny makes the departure of Parenteau uglier, too.

At five on five, the two were Colorado's top regular forwards in Corsi percentage. Moreover, when they were on the ice, the Avalanche scored 56.7 percent and 54.5 percent, respectively, of all goals tallied.

Matt Slocum/Associated Press

Newcomer Briere wasn't exactly a dud in Montreal, but he was basically treading water in terms of both goals and Corsi. He also slipped down the Canadiens' lineup in the postseason—it's difficult to understand why the Avs preferred him to Parenteau.

The net result is that Colorado moved two critical five-on-five pieces for a pair of players who are going to need to shoot the lights out because they aren't likely to win the shots battle.

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On defence, the Avs made something of a name addition by trading for Stuart, but again, it isn't obvious that he's a big upgrade on the still-unsigned Andre Benoit.

Benoit played key minutes on defence, taking on second-pairing opponents and playing a role on both special teams. His underlying numbers hovered around the team average.

Stuart played similar minutes for much of the year in San Jose, and he underperformed compared to the team's totals. The Sharks were a better team, but even allowing for that, this is probably only a wash. Benoit also played power-play minutes, but Colorado should be able to replace those internally.

The only obvious upgrade is the move from Brad Malone to Jesse Winchester, and that's happening far enough down the lineup that its impact will be muted.

However, Colorado's biggest problem isn't that it seems to have downgraded in free agency.

Its biggest problem is that last year's results were fuelled by an uncanny shooting accuracy at five on five (8.8 percent at even strength, the second-best total in the NHL) and the brilliance of goalie Semyon Varlamov, who went from a miserable .903 save percentage to a brilliant .927 total.

Doug Pensinger/Getty Images

Few teams can sustain a shooting percentage so far above the NHL average year over year, and if the Avalanche fail to, their goal totals will take a big hit.

Varlamov is almost certainly better than his 2012-13 .903 save percentage performance, but his career average is significantly lower than what he did in 2013-14. If he steps back toward his career average, Colorado is going to allow a lot more goals than it did last season.

How big of a drop are we talking? If Varlamov goes back to a career-average save percentage and the Avalanche shoot at an NHL-average rate in 2014-15 (the team's shooting percentage was below league averages in both 2011-12 and 2013 in five-on-five situations), the team would score 20 fewer goals and allow 21 more.

As the Avs only posted a plus-30 goal differential in 2013-14, a 41-goal drop would likely put them outside the playoffs in the competitive West next season.

Major improvements were needed over the summer. We haven't seen them yet.